Affixing characters to transparent drums



June 10, 1947. J, L, SML W 2,421,764

' AFFIXING CHARACTERS T0 TRANSPARENT DRUMS Filed Oct. 23, 1944 Patented June 10, 1947 AFFIXIN G CHARACTERS TO TRANSPARENT DRUMS Joseph L. Swallow, Lombard, Ill., assignor to Wells-Gardner & 00., Chicago, 111., a corporation of Illinois Application October 23, 1944, Serial No. 560,083

4 Claims.

This invention: relates to a means and method whereby to affix desired characters to the interior surfaces of drums which are transparent or translucent. A drum of this character is commonly used. as part of the dial mechanism of a radio receiving set. When in use, the drum may be mounted for rotation, and may also receive illumination. from a light source which is positioned close to be outside of the drum.

Little or no difficulty is encountered in printing, impressing, or transferring desired characters to a flat sheet of material which thereafter is rolled into a drum of cylindrical form. Any drum so made, however, is characterized by a seam along the line of th juncture of its opposite edg'es, It is possible to eliminate this undesirable feature altogether if the drum be produced initially in the form of a cylinder, but in that event it becomes difficult to affix the desired characters to the interior of the completed drum.

It is with the object and purpose of simplifying the means and method whereby characters may be affixed to the interior of a transparent drum of cylindrical form that my invention is primarily concerned. If the drum be made of thermoplastic material, it is possible with the aid of heat to soften its interior surface whereby the impressed characters may be embossed or be slightly sunken in place. The characters may be conveniently carried upon a vehicle such as decalcomania label from which they are readily transferable, with the aid of a fluid pressure, to the interior surface of the drum. In the description to follow, a decalcomania label will be referred to as a suggestive vehicl for the characters which are to be transferred to the drum, the latter being usually transparent, or at least translucent to some degree. It is important merely that the characters on the interior surface of the drum shall be discernible through its body to the exterior thereof.

In the accompanying drawing I have illustrated diagrammatically in Figure 1 the several parts of a simple apparatus for effecting a transfer of characters from a, vehicle to the interior of a transparent drum. Fig. 2 is an enlarged view in elevation, with end portions broken away, showing the positions of the expansible mounting tube whereon the vehicle is carried and the transparent drum to whose interior surface the characters are to be transferred. In Fig. 3 is an enlarged detail in section showing the characters in sunken position upon the interior surface of a thermoplastic drum.

The apparatus herein illustrated comprises an expansible mounting tube T which may be produced conveniently from some such material as rubber, natural or synthetic. Within opposite ends of the tube are fitted closure heads 4 and 5; the tube ends then being pressed tightly against the periphery of these heads as by clamp bands 6. Tie rods 1 which interconnect the closures to. maintain them a fixed distance apart serve to confine expansion of the mounting tub-e to radial directions.

An axial opening I0 is formed through the closure head 5 from whose outer face is extended a nipple ll upon which is fitted a conduit [2, flexible or otherwise, leading to a source of fluid pressure such as air or water. To make the connection tight, a clamping band M i shown as extended around the conduit at the point of its engagement with the nipple. In the conduit may be interposed a three-way valve 15 also a pressure gauge l6. By some such means as this I provide for admitting fluid pressure through the valve into the interior of the expansible mounting tube, the pressure being then registered on the gauge. By further manipulation of the valve, the fluid pressure may be released to permit contraction of the mounting tube.

Upon the exterio surface of the expansible tube are mounted characters C which it is desired to transfer to the interior surface of a transparent drum D. These characters may be of different kinds, either separate from each other, or carried upon a common vehicle. They may also be formed in a die suitable for transferring the same impressions to the drum with the aid of a requisite heat and pressure.

Another way for effecting a transfer of the characters C is to have them mounted upon a vehicle such as a decalcomania label L which with some advantage may be initially formed into a tube. A suggestive method of procedure is then as follows:

Upon the mounting tube the vehicle-a decalcomania label L, for example-is first placed. Some fluid pressure should then be admitted into the interior of the mounting tube so that it will enlarge sufficiently to engage tightly with the surrounding vehicle, if the latter itself be in the form of a tube. In the case of a decalcomania label, wetting then follows, as by dipping or spraying, but with other kinds of characters the precise step requisite for conditioning their outer surfaces for adhesion to the drum may vary. The mounting tube, with characters thereon conditioned for adhering, is then inserted within the cylindrical drum by an endwise movement of one of these parts relative to the other. When the parts are correctly positioned, the valve is operated to admit further fluid pressure to a point requisite for forcing the wet transfer label with a uniform pressure against the interior of the cylindrical drum. Under such conditions the characters C upon the mounting tube are free to be transferred to the interior surface of the drum to Which they will remain adhered by the adhesive which they carry. In the event that the walls of the drum are too thin to withstand the applied internal pressure, the drum may be encased within a surrounding reenforcing shell S. When so disposed, the thin Walls of the drum will be adequately protected.

It is possible to vary the procedure as to time, temperatures, pressure, etc. depending upon the materials used, results desired, etc. For example, if the drum be formed of thermoplastic material, the fluid pressure should be desirably heated so as to soften the drum interior at the time the expansible tube is pressed thereagainst. Under such conditions it is possible to employ a die suitable for transferring impressions to the interior of the drum. In fact, any characters of appreciable thickness may be sunk slightly into the in terior surface of the drum as suggested in Fig. 3. The operation is completed by reducing the pressure sufficiently to contract the mounting tube whereupon it becomes free for withdrawal from the drum, leaving only the characters that have been transferred therefrom on to the interior surface of the drum.

I claim:

1. The method of adhering characters to the interior surface of a transparent preformed drum which comprises the steps of fitting a tubular decalcomania label over a radially expansible mounting tube prior to expansion, expanding the mounting tube slightly outwardly in a radial direction against the surrounding decalcomania label to secure the one firml to the other, wetting the outer surface of the decalcomania label, relatively advancing within the drum in spaced relation therewith the slightly expanded mounting tube with the wetted decaloomania label thereon to a desired position for transfer of the decalcomania characters to the drum, further expanding the mounting tube in a radial outward direction to press the tubular decalcomania label against the interior surface of the drum for adhesion thereto, and contracting the mounting tube to produce a spaced relation separation of the mounting tube from the characters transferred from the decalcomania label to the interior of the drum to permit removal of the drum and remaining parts of the label without contact with the characters transferred to the drum and without affecting the rigid form of the drum.

2. The method of adhering characters to the interior surface of a transparent preformed drum which comprises the steps of relatively advancing within the drum a wetted decalco-mania label containing characters and carried by an expansible mounting tube, expanding the mounting tube 4, from a position in spaced relation with the interior of the drum to a position in contact with the drum and to apply pressure to the label to affix the label characters upon the interior surface of the drum, and contracting the tube to produce a spaced relation separation of the remainder of the label and the drum for removal of the tube and the label from the drum without contact with the characters impressed on the drum and without affecting the rigid form of the latter.

3. The method of adhering characters to the interior surface of a rigid preformed transparent drum which comprises the steps of placing on the exterior surface of a radially expansible mounting tube releasable transferable characters, Wetting the releasable characters, relatively advancing the mounting tube within the drum in spaced relation therewith and with the characters out of contact with the drum, and while so inserted expanding the mounting tube radially in an outward direction against the interior of the drum to press the characters against the inner surface'of the drum to transfer the releasable characters thereto, finally contracting the mounting tube to produce a spaced relation separation of the tube from the drum and the characters applied to the latter, and withdrawing the mounting tube from the drum while in spaced relation therewith leaving the characters adhered to the interior of the drum and without affecting the rigid form of the drum.

4. The method of adhering characters to the interior surface of a rigid transparent preformed drum which comprises the steps of placing upon an expansible mounting tube a vehicle containing a plurality of releasable transferable characters, wetting the releasable characters, introducing the mounting tube with the vehicle thereon into the drum to a position within the drum in spaced relation therewith, expandin the tube outwardly in a radial direction to press the characters against the interior surface of the drum for adherence thereto without affecting the rigid form of the drum, and withdrawing the mounting tube from the drum while in spaced relation with the same.

JOSEPH L. SWALLOVT.

REFERENKJES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Great Britain Mar. 10, 1932 

